Sesay was an adept at languages. His first language was the Temne language of Sierra Leone, but also learned English and Federation Standard quickly due to his parents’ professional contacts. Among the other Terran languages Sesay spoke were Arabic, French, and Swahili. The first extrasolar language Sesay learned was Vulcan, which he appreciated due to its musical origins. In addition to his linguistic abilities, Sesay was a star athlete in primary and secondary school, where his varsity letter was in association football (aka soccer).

He entered Starfleet Academy in 2292 and, among his other accomplishments, became captain of the Academy's association football team. Sesay graduated 17th of 800 with the class of 2296, whereupon he was granted the rank of ensign and posted to the USS Bluford as a communications specialist (xenolinguistics).